Water has many unique characteristics. One of these properties is water’s unusual ability to absorb large quantities of heat without much change in temperature. This characteristic is the specific heatcapacity, Cp.

When water absorbs 4.184 Joules of heat, the temperature of one gram of water will increase by 1 C°. Relatively speaking, this is an enormous amount of heat energy. Coastal states like Florida, which are surrounded by water, maintain relatively stable climates with moderate temperatures. This is because water can absorb or release a great deal of heat without experiencing huge fluctuations in temperature.

By comparison, look at the heatcapacity of copper. 1 gram of copper will rise in temperature by 1 C° when just 0.385 Joules of heat is absorbed. This low specific heatcapacity indicates that copper is a good conductor of heat. You might predict that applying a small amount of heat will make the temperature of a gram of copper skyrocket while the same amount of heat hardly makes the temperature of one gram of water rise at all.